WBGT and Heat Index

• The WBGT is not quite the same as heat index.
• The WBGT is taken in the Sun to account for the intensity and angle of the Sun’s energy striking the Earth.
• It also uses wind measurements to get a more accurate picture of how people respond to hot weather conditions.

Comparison with Heat Index

	WBGT	Heat Index
Measured in the Sun	Y	N
Measured in the Shade	N	Y
Uses Temperature	Y	Y
Uses RH	Y	Y
Uses Wind	Y	N
Uses Cloud Cover	Y	N
Uses Sun Angle	Y	N

Source: www.srh.noaa.gov/tsa/